Oxygen tent atmosphere conditioning apparatus and method



1967 R. CAMETO ETAL OXYGEN TENT ATMOSPHERE CONDITIONING APPARATUS ANDMETHOD 2 Sheets-Sheet 1 Filed Jan.

INVENTORS LEON ROBERT CAM ETO I HARRI 5: By 5%, MM *w fiq WILLIAM R.EVANS RALEIGH J.

2 Sheets-Sheet 2 L. R. CAMETO ETAL OXYGEN TENT ATMOSPHERE CONDITIONINGAPPARATUS AND METHOD Feb. 28, 1967 Filed Jan.

T INVENTORS LEON ROBERT CAMETO WILLIAM R. EVANS RALEIGH J HARRIS By 7I'M 47' TORNEYS United States Patent OXYGEN TENT ATMOSPHERE CONDITIONINGAPPARATUS AND METHOD Leon Robert Cameto, William R. Evans and Raleigh J.Harris, all of Oakland, Calif., assignors to Mist 0 Gen Equipment Co.,Oakland, Calif.

Filed Jan. 2, 1962, Ser. No. 163,453 Claims. (Cl. 128191) This inventionrelates to a system for conditioning the atmosphere in an oxygen, orpatient treatment, tent. The atmosphere, predominantly oxygen enrichedair, in an oxygen tent often becomes uncomfortable for the patienttherein because of the heat radiated by his body in the small enclosedspace. In addition, the atmosphere in the tent is often maintained in amoist, humid condition because of the addition of vapor carryingmedicants which increases the .discomfiture.

Heretofore, systems for conditioning, primarily cooling, the tentatmosphere have withdrawn it from the tent, passed it through coolingducts and filters, added the required oxygen and vapor, and recirculatedthe atmosphere to the tent. Although such prior systems have adequatelyconditioned the air in tents, they have become easily contaminated bythe tent atmosphere which the patient has exhaled. Because of the manyintricate passageways and crevices in such equipment and its necessarysize it has been impossible to sterilize by ordinary cleaning processes.In order to safely reuse such equipment on succeeding patients it hasbeen the practice to leave the equipment idle for an extended time inorder to assure that harmful bacteria will not remain to contaminate thenew patients tent atmosphere. This, of course, causes substantial nonuseof the equipment.

Another object of this invention is the provision of structure and anarrangement thereof whereby contamination of the system from contactwith the atmosphere within any oxygen tent is restricted to only theexterior readily sterilized surfaces of a relatively small portion ofthe system, and which portion is readily separated from the remainderfor sterilization thereof.

It is a further object of this invention to provide a novel method forconditioning the atmosphere in any oxygen tent.

Yet another object of the invention is the provision of improvedstructure in the portion of a cooling system that is adapted to bepositioned within an oxygen tent for cooling the atmosphere within suchtent, and which portion is readily detached from the remainder of thecooling system.

Yet a further object of this invention is the provision of a method forconditioning the atmosphere in a patient treatment tent, in which methodheat is withdrawn from the tent without withdrawing a substantialportion of such atmosphere.

In the present system no special attempt is made to circulate the airwithin the tent other than what circulation occurs in the form ofconvection currents caused by the presence of a cooling element withinthe tent.

The present invention isolates the coolant in the cooling system fromthe air in the tent so that no contamination of the coolant is possible,and the present system is so arranged that all parts or portions thatmay become contaminated are readily separated from the rest of thesystem for sterilization.

In the drawings:

FIG. 1 is an isometric view that is illustrative of the systemgenerally.

FIG. 2 is an enlarged cross sectional view taken along line 22 of FIG.1.

FIG. 3 is a fragmentary, enlarged cross sectional view 1 taken alongline 33 of FIG. 1.

3,306,289 Patented Feb. 28, 1967 FIG. 4 is a side elevational view ofthe refrigeration apparatus within a cabinet, as seen from the rear sideof the cabinet shown in FIG. 1, the latter being in cross section andwith part of the view schematically illustrating the heat exchanger thatis adapted to be positioned within the tent to be air conditioned.

FIG. 5 is an enlarged side elevational view of the heat exchanger unit,as seen from the reverse side shown in FIG. 1.

FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 5.

Referring to the drawings, the numeral 1 generally designates arefrigeration unit or assembly which functions to remove heat energyfrom a heat exchanger, generally designated 2, adapted to be supportedwithin an oxygen tent 3 (FIG. 1) for cooling the air within said tent.In the embodiment described herein the refrigeration unit 1 circulates aliquid coolant through heat exchanger 2 to withdraw heat from it. Thepreferred coolant is water mixed with alcohol (to prevent its freezing)and it will hereinafter be referred to as water or coolant.

A water conduit 4 (FIG. 4) receiving warm water from the heat exchanger2 is coiled around a cooling tank 6, supported in a cabinet 5 withinwhich the refrigeration unit is enclosed. Conduit 4 empties into coolingtank 6 where the water is cooled by a refrigerant in coil 7, which alsosurrounds tank 6.

A conventional compressor 8 and condenser 9 are connected with coil 7for supplying the cooled refrigerant to the latter, and the refrigerantis returned to the compressor through pipe 10.

The sole function of the refrigerating system is to cool the water thatis circulated through the heat exchanger 2, and any suitable andconventional control means 11 may be employed for controlling thetemperature of the water. Such control means includes ordinarythermostatic controls having settings manually adjusted by the usualcontrol knob conveniently located on the top of the cabinet of FIG. 1,as indicated at 12.

Make-up water may be added to the system from a closed supply reservoir13 having a delivery pipe 14 (FIG. 4) leading to the bottom of tank 6,and an air vent pipe 15 communicating between the upper end of saidreservoir and the upper end of tank 6 equalizes the an pressure in thetank and reservoir 13. Preferably reservoir 13 has a transparentsidewall and is mounted to be visible for indicating the level of waterin the system.

Outside the cabinet is a supply tank (not shown) contaming oxygen orother breathable gas under pressure having the usual pressure and flowcontrol valves thereon from which a hose 16 leads into the cabinet (FIG.4) where it divides into flexible lines 17, 18 that terminate infittings 19, 20 mounted on top of the cabinet. Fittings 19, 20 includequick detachable couplers serving to connect lines 17, 18 with oxygenhoses 21, 22. Each said fitting also incorporates a check valve to closelines 17, 18 when hoses 21, 22 are disconnected and fitting 19 may alsohave incorporated therein a needle control valve for adjusting the flowof oxygen into hose 21. Fitting 20 may include a manually operable valvefor opening and closing hose 22 to flow of oxygen from the oxygen supplytank. I The tent 3 (FIG. 1), which is a conventional flexibleplastic-walled drape, is adapted to be suspended from a horizontal bar23 that extends over the tent transversely of the latter. Cross rods 24,extending horizontally through said bar 23 at right angles to thelatter, have eyes 25 or hooks at their outer ends from which hangers 26extend to and connect with the tent for supporting the latter in thedesired position.

One end of bar 23 is secured to the upper end of a vertical post 28. Thelower end of said post extends through a collar 29 and into cabinet 5(FIG. 3), said collar being secured on the upper wall of said cabinet. Athumb screw extending through collar 29 adjustably secures post 28 atthe desired elevation, and it also functions to hold the bar 23 at thedesired angle relative to the cabinet, since the post 28 may be revolvedwhen screw 30 is loosened.

A fitting 31 is also secured on post 28 adjacent to the lower end of thelatter by a pair of set screws 32. The post 28 extends verticallythrough a sleeve-like portion 33 of said fitting, and an enlargementportion 34 projects from one side of said fitting. Portion 34 may beconnected to portion 33 by a vertically displaceable dovetail connection27. Such disconnectable portion 34 is formed with a horizontal,open-ended through bore 35 (FIG. 3) through which extends one end of acylindrical pipe 36. A screw 37 extends through one side of saidenlargement portion and secures the end of pipe 36 to portion 34.

By this structure it is apparent that the pipe 36 may be detached frompost 28 by raising said pipe and separating portion 34 of fitting 31from portion 33.

Pipe 36 extends from the fitting 31 into the tent 3 through an opening38 formed in the side wall 40 of the tent that is adjacent to post 28and to said fitting 31. The portion 41 of the pipe 36 that is withinsaid tent may extend any desired distance across the tent, and isgenerally above the bed 42 on which the patient may be lying and overthe head portion of which the tent is adapted to be suspended.

The upper side of said portion 41 is formed with a slot or elongatedopening 43 (FIG. 6) extending longitudinally of said portion, and intowhich the lower marginal portion of heat exchanger panel 39 extends.

The heat exchanger panel 39 may be formed by a pair of verticallydisposed plates 44, 45 (FIG. 6) having a plurality of complementary,opposedly opening recesses formed in their adjacent sides, whichrecesses are interconnected by suitably positioned return bends forforming a continuous conduit 48 to conduct coolant therethrough. Theplates 44, 45 are welded or otherwise secured fiat together around saidrecesses. These recesses that coact to form conduit 48, may be expandedin the plates after the remaining portions are secured together in aconventional manner, or they may be die formed and the plates weldedtogether. In any event, the marginal portion along the lower edge of theheat exchanger panel is a horizontally extending vertically disposedplatelike extension projecting downwardly below the lower horizontal runof conduit 48 and through slot 43 into the portion 41 of pipe 36. A pairof vertical posts 46 secured to portion 41 serve to support the oppositemarginal edges of panel 39.

In the embodiment herein illustrated the heat exchanger 2 is a panel ofsubstantial area which is cooled by circulation of coolant through theextensive conduit therein for absorbing heat energy from the tentatmosphere and transferring it to the refrigerating unit.

There are two quick detachable couplings 49, on the cabinet 5 (FIG. 1)that couple hose lines from the ends of conduit 48 with the conduit 4emptying into cooling tnk 6 and with the outlet therefrom. A hose ortube 52 may connect the outlet end of conduit 48 with coupling 50whereas the hose or tube 51 connects the inlet end with coupling 49.These hoses extend into pipe 36 through slot 43 and then out throughopenings in a sealing plug 53 (FIG. 2) in the end of pipe 36 that isadjacent to the cabinet 5 to the couplings 49, 50. Such end of pipe 36functions as a housing for the tubes carried therein.

Within the cabinet (FIG. 4), a pressure line 54 having a pump 55interposed therein connects the outlet from tank 6 with the coupling 49and hose 51 while the pipe 4 from coupling 50 will connect hose 52 withthe inlet into tank 6. It is obvious that the inlet and outlet hoses maybe reversed as desired.

As already mentioned, thermostatic control means 11 is adapted to be setto control the temperature of the water or coolant, and water branchlines 57 from the tank are associated in the usual manner with saidthermostatic control means.

Oxygen lines 21, 22 extend through plug 53 into the same end of pipe 36as the water lines 51, 52. One of these oxygen lines 21 extends into aconventional atomizer or nebulizer 58 which is adapted to be supportedin the tent 3 (FIG. 1). This nebulizer is connected by a tube 59 with areservoir 60' that is outside the tent and may be supported on post 28on the cabinet 5. Reservoir 60 holds the liquid that is to be dischargedin vapor form into the tent to control the humidity of the atmospherewithin the tent. The other oxygen line 22 also extends through plug 53into pipe 36 and when the valve in fitting 20 is opened admits oxygen tothe tent to flush the atmosphere in the same with pure oxygen.

The oxygen or air flow in line 21 actuates the nebulizer in a knownmanner to aspirate liquid from the receptacle into the nebulizer foratomization and discharge thereof into the tent with the oxygen. Tube 59that connects the nebulizer with the reservoir 60 has disposed within ita suction tube 61 (FIG. 2) which carries the liquid from the reservoirto the nebulizer nozzle where it is vaporized and mixed with the oxygenfrom line 21. The larger particles of liquid which are not sufficientlyvaporized drain back into reservoir 60 through the outer tube 59.

The nebulizer not only humidifies the atmosphere in the tent but alsoassists in circulating it. Medicaments may be added to the vaporgenerated. by the nebulizer for desired medical treatments. Since gas isbeing continually added there is a continual overflow of atmosphere fromthe tent due to normal leakage at the borders where it is tucked aroundthe bed and the patient. This added gas may be any oxygen, air, or otherbreathable gas under pressure depending on the patients requirements.

Normally the atmosphere in the tent will be maintained at a highhumidity because the added oxygen is usually quite dry and because amedicated, humid atmosphere is often beneficial to the patient. Such anatmosphere would be most uncomfortable, due to the added heat radiatedfrom the patients body and expired by him, were it not for the coolingeffect of heat exchanger 2. The moisture will, however, tend to condenseon the cooler surfaces of the heat exchanger panel 39.

The condensate collecting on the heat exchanger panel will drain intothe pipe 36 through slot 43 and will be drained from pipe 36 (which ispreferably slightly inclined for this purpose) through a hose line 63(FIG. 2) that extends from plug 53 to a closed drain receptacle 64. Thisreceptacle may be supported in an outwardly opening recess 65 formed inthe cabinet 5 and is preferably sealed to avoid contamination of any ofthe refrigerating unit. It may be noted that the lower marginal portionof the heat exchanger 39 is spaced from the edges of slot 43 (FIG. 6)where it extends into the portion 41 of pipe 36, thus insuring drainagefrom both sides of the heat exchanger panel into said pipe 36.

The operation of the system is believed to be clear. The cooled waterfrom the tank 6 is circulated through the heat exchanger in a circuitthat is completely sealed against contact with the atmosphere in tent 3.The flow of oxygen through lines that extend into the pipe 36 is alwaysinto the tent 3 where the oxygen is discharged, a portion of it beingwith atomized liquid.

In effect, the atmosphere in the tent, which becomes contaminated by thepatient during use, is completely isolated from the refrigerating andoxygen-adding systems. It is these latter systems that, because of theircomplex passageways and associated electro-mechanical equipment, arevery difficult to maintain in sterile condition and are impossible torapidly sterilize by steam, as in an autoclave.

In the embodiment herein described only the condensate draining from theheat exchanger and the gross liquid particles draining from thenebulizer pass outside the tent 3 and these liquids are received insealed and sterilizable receptacle 64 and reservoir 60. If desired,receptacles can be provided within the tent for receiving these drainingliquids, although this practice is not deemed necessary because thepossibility of contamination from these sources is negligible.

The jar or reservoir 60, the receptacle 64, the'quick detachablecouplings connecting the water lines with the heat exchanger 2, and thequick detachable couplings that connect the oxygen lines with thecabinet 5 are all outside the cabinet, hence nothing that contacts thecontaminated air within the tent passes into the cooling system withinthe cabinet. This eliminates the necessity for filters and the like,which are used in systems in which the tent atmosphere is recirculated.

Sterilization of the parts that in any way come into contact with thecontaminated air is greatly facilitated by their arrangement'and thefact that they are readily separated from the cabinet housing therefrigerating unit. The jar 60 and receptacle 64 may readily be removedfrom the cabinet and the oxygen lines and Water lines are quicklydetached Where they are coupled with lines from the oxygen supply tankand water coolant tank. The heat exchanger 2 may quickly be detachedfrom the post 28, by separating the dovetail connection 27, and thelines 21, 22, 51, 52, 59 and 63 may be removed therewith (along with jar60 and receptacle 64). All of these parts may be readily and completelysterilized in an autoclave or the like and will thereafter be availablefor immediate reuse.

Since the refrigerating unit 1 and its cabinet 5 always remain isolatedfrom and uncontaminated by the tent atmosphere, they may be employedwith other sterilized heat exchangers for other patients in immediatesuccession. Sterilization of the tent 3 and bed 42 is, of course,accomplished by conventional means, or the tent may be disposed of afteruse.

In operation, it may be said that the method of conditioning theatmosphere within the oxygen tent is one in which oxygen or otherbreathable gas under pressure is injected into the tent, together withthe moist vapors from the nebulizer. A slight pressure above that of theoutside atmospheric pressure is thereby created so that the atmospherewithin the tent will be permitted to sub stantially continuously escapefrom the tent, which escape will normally be, for the most part, aroundthe lower edges of the tent. The atmosphere within the tent will usuallybe an oxygen-enriched air and moist vapor mixture.

The mixture will become heated from the body heat and respiration of thepatient, and this heat is withdrawn from the mixture by the cooler,which in the present instance is illustrated as .a heat exchanger.

As a result, a downward moving current of cooled atmosphere, byconvection, will flow to the head of the patient, and since the oxygenand moist vapors are injected into the tent above the patients head,these will be carried downward with the said convection current to thehead of the patient. The atmosphere within the tent will escape into theatmosphere outside the tent, but contrary to conventional airconditioning systems, none of the atmosphere is withdrawn other thanthat which is permitted to escape.

The oxygen-vapor content of the tent is thereby maintained againstescape or removal from the tent other than the portion that is permittedto escape into the outside atmosphere.

Under the above circumstances, none of the atmosphere within the tentcan enter the cooling system itself, but

can only contact the portion of outside surface of the elements of suchsystems as may be within the tent.

Although a specific embodiment has been described herein, suchmodifications as would appear to one skilled in the art are understoodto be within the spirit and scope of the invention.

We claim: 1. Apparatus for conditioning the atmosphere within a patienttreatment tent comprising:

(a) a nebulizer (b) a conduit fully enclosing and sealing fromcontamination by said atmosphere a coolant adapted to be circulatedthrough said conduit, (c) said conduit including a heat exchanger andinlet and outlet portions for respectively conducting said coolant intosaid heat exchanger and out of the latter upon said circulation,

(d) said nebulizer and said heat exchanger including said inlet andoutlet portions of said conduit being adapted to be positioned withinthe atmosphere within said tent,

(e) means for so positioning said nebulizer, heat exchanger and saidinlet and outlet portions and (f) said nebulizer including a gas pipeline and a fluid pipe line connected therewith for conducting abreathable gas and a fluid to said nebulizer,

(g) said conduit further including heat removing means for removing heatfrom said coolant upon said circulation of the latter, and

(h) a gas supply tank connected with said gas pipe line for supplyingbreathable gas to said nebulizer,

(i) detachable couplings in said conduit and gas line for disconnectingsaid heat exchanger and said nebulizer from said heat removing means andfrom said gas supply tank to enable sterilization of said heat exchangerand said nebulizer independently of said heat removing means and saidgas supply tank.

2. In the combination as defined in claim 1,

' (j) means securing said nebulizer to said heat exchanger for handlingas a unit with said heat exchanger,

(k) a housing rigid with said heat exchanger having an inner end at saidheat exchanger and an outer end spaced therefrom and which outer end isadapted to extend through and project from a wall of said tent when saidheat exchanger and said inner end are positioned within said tent,

(1) said inlet and outlet portions of said conduit and said gas pipeline extending through and enclosed by said housing and (m) saiddetachable couplings adapted to be outside said tent adjacent to saidouter end of said housing.

3. In a cooling system for cooling the atmosphere within an oxygen tent;

(a) a vertical post adapted to be rigidly held at different positionsoutside such tent relative to the latter;

(b) means for so holding said post;

(0) a horizontally extending rigid tubular member;

(d) quick removable means for securing said member to said post forremoval of said member from said post upon upward movement of saidmember relative to said post;

(e) said member projecting laterally from said post a sufi'icientdistance to extend at one end thereof through a side wall of such tentand into the latter when said post is alongside such side wall andoutside the tent;

(f) a drain collector for receiving condensate from a heat exchanger,secured to said one end of said tubular member and supported by thelatter;

(g) a heat exchanger supported on said drain collector and adapted tothereby be supported within such tent by said member and said post;

(b) said heat exchanger having a passageway therethrough for a coolant,and having an inlet at one end of said passageway for such coolant andan outlet at its opposite end for said coolant;

(i) separate fluid conducting lines respectively connected with saidinlet and said outlet and extending through said tubular member tooutside such tent when said heat exchanger and said drain collector aresupported within said tent by said post.

4. The combination as defined in claim 3, plus;

(3') said tubular member being open at the end thereof that is oppositeto said drain collector through which said separate fluid conductinglines extend;

(k) a drain line extending from said drain collector through saidtubular member and out of the said open end thereof;

(1) quick coupling means respectively on said separate fluid conductinglines and said drain line, adjacent to the said open end of said tubularmember for releasably connecting them with other portions of the coolingsystem.

5. In a cooling system for cooling the atmosphere within an oxygen tent;

(a) a vertical post adapted to be rigidly held at different positionsoutside such tent relative to the latter;

(b) means for so holding said post;

(c) a horizontally extending rigid tubular member;

(d) quick removable means for securing said member to said post forremoval of said member from said post upon upward movement of saidmember relative to said post;

(e) said member projecting laterally from said post a sufficientdistance to extend at one end thereof through a side wall of such tentand into the latter when said post is alongside such side wall andoutside the tent;

(f) a heat exchanger;

(g) means supporting said heat exchanger on said tubular member at theend of the latter remote from said post for holding said heat exchangerat an elevated point within said tent when said post is outside saidtent;

(h) said means for holding said post including a portable housing andconventional refrigeration apparatus having a circulating system for acoolant;

(i) said heat exchanger including a passageway for a coolant having aninlet at one end thereof and an outlet at the opposite end;

(j) coolant conducting lines respectively connected with said inlet andsaid outlet extending through said tubular member and out of the latterat a point adjacent to and outside said housing; and,

(k) quick detachable couplings at said point for detachably couplingsaid lines with the coolant circulating system of said refrigerationapparatus, whereby said tubular member, heat exchanger and coolantconducting lines may be separated from said refrigeration apparatus as aunit.

References Cited by the Examiner UNITED STATES PATENTS 1,858,400 5/1932Koehler 12819l.1 1,913,347 6/1933 Taylor 128191.1 1,971,408 8/1934Heidbrink ct al. 128l91.1 2,190,613 2/1940 Sittler 128191.1 2,882,0264/1959 Eichelman 128-194 X 2,903,863 9/1959 Coning 62-291 X 3,000,3799/1961 Viers 128191 3,040,742 6/1962 Eichelman 128--191.1 3,050,0588/1962 Andrews 128191 FOREIGN PATENTS 28,746 1909 Great Britain.

RICHARD A. GAUDET, Primary Examiner.

JORDAN FRANKLIN, Examiner.

W. E. KAMM, H. PEZZNER, D. S. BURKS,

Assistant Examiners.

1. APPARATUS FOR CONDITIONING THE ATMOSPHERE WITHIN A PATIENT TREATMENTTENT COMPRISING: (A) A NEBULIZER (B) A CONDUIT FULLY ENCLOSING ANDSEALING FROM CONTAMINATION BY SAID ATMOSPHERE A COOLANT ADAPTED TO BECIRCULATED THROUGH SAID CONDUIT, (C) SAID CONDUIT INCLUDING A HEATEXCHANGER AND INLET AND OUTLET PORTIONS FOR RESPECTIVELY CONDUCTING SAIDCOOLANT INTO SAID HEAT EXCHANGER AND OUT OF THE LATTER UPON SAIDCIRCULATION, (D) SAID NEBULIZER AND SAID HEAT EXCHANGER INCLUDING SAIDINLET AND OUTLET PORTIONS OF SAID CONDUIT BEING ADAPTED TO BE POSITIONEDWITHIN THE ATMOSPHERE WITHIN SAID TENT, (E) MEANS FOR SO POSITIONINGSAID NEBULIZER, HEAT EXCHANGER AND SAID INLET AND OUTLET PORTIONS AND(F) SAID NEBULIZER INCLUDING A GAS PIPE LINE AND A FLUID PIPE LINECONNECTED THEREWITH FOR CONDUCTING A BREATHABLE GAS AND A FLUID TO SAIDNEBULIZER, (G) SAID CONDUIT FURTHER INCLUDING HEAT REMOVING MEANS FORREMOVING HEAT FROM SAID COOLANT UPON SAID CIRCULATION OF THE LATTER, AND(H) A GAS SUPPLY TANK CONNECTED WITH SAID GAS PIPE LINE FOR SUPPLYINGBREATHABLE GAS TO SAID NEBULIZER, (I) DETACHABLE COUPLINGS IN SAIDCONDUIT AND GAS LINE FOR DISCONNECTING SAID HEAT EXCHANGER AND SAIDNEBULIZER FROM SAID HEAT REMOVING MEANS AND FROM SAID GAS SUPPLY TANK TOENABLE STERILIZATION OF SAID HEAT EXCHANGER AND SAID NEBULIZERINDEPENDENTLY OF SAID HEAT REMOVING MEANS AND SAID GAS SUPPLY TANK.